Comparison of topical permethrin 5% vs. benzyl benzoate 25% treatment in scabies: a double-blinded randomized controlled trial

BACKGROUND: Scabies is a pruritic, parasitic infestation of the skin. Increasing incidence has been reported from high income countries in the past years. Reports have indicated a reduction in the sensitivity of scabies mites to the standard treatment of choice, topical 5% permethrin.

OBJECTIVES: First, to evaluate the head-to-head efficacy of two topical scabicides, 5% permethrin and 25% benzyl benzoate (BB), in the treatment of scabies using the same administration modality. Second, to address potential confounding factors, like incorrectly performed treatment and hygiene measures.

METHODS: In total, 110 patients with dermoscopy-verified scabies infestation were enrolled and double-blinded randomized into two equally sized groups. 55 patients received topical 5% permethrin and 55 patients received topical 25% BB, both for daily use over a period of three consecutive days. Treatment outcome was evaluated by dermoscopy at a 3-week follow-up visit.

RESULTS: Treatment resulted in a dermoscopy-verified cure rate of 27% in the permethrin group and 87% in the BB group. Tolerability and safety profile of 5% permethrin cream was excellent, while BB emulsion produced burning sensations in 24%.

LIMITIATIONS: Single center study recruitment.

CONCLUSION: Topical permethrin demonstrated a lack of efficacy in the majority of cases whereas benzyl benzoate demonstrated an excellent cure rate and reasonable tolerability. Considering the reduced sensitivity of scabies mites to 5% permethrin, our results suggest that benzyl benzoate is an appropriate first-line therapy in the treatment of scabies.

TRIAL REGISTRATION: drks.de, ID DRKS00031062.